Hello,
I googled this issue, where the inductance probe shows triggered/open almost randomly on pronterface. No matter what I do, LED on or off, on the probe, the M119 command sends me back inconsistent results. Nothing was perfectly clear as to why this was happening when I searched. I thought at first it was my resistors, maybe I wasnt giving the ramps enough voltage to see the high position. I am at 4.4v hi and about 0.4v low, this should be enough for ramps logic. I measured with voltmeter and the sensor works. I am not sure why my ramps isnt picking it up consistently. Some people say its the probe malfunctioning, other searches turn up that the ramps is fried, and I also read somewhere that the pullup resistor option in the config.h file needs to be commented out. I honestly dont ever remember commenting this out on my other build, and that build works fine. Any suggestions would be appreciated, thank you.